Figure 1

Forms of academic exchange. The most common opportunities for scientists to meet separated by their drive for novelty and development (Y axis) and their duration (X axis), the former as a subjective consensus among the authors. Sprints, Codefests and Hackathons dominate for their focus on joint new developments, the transfer of expertise for new scientific questions, the distribution of infrastructure and a network of trust between the contributors. Longer programs like the Summer of Code combine many types of interactions over a long time, with the difference that those participating may be assigned different, specific roles - say as mentor and learner.